How a battery earns in PJM

PJM is the largest US power market, coordinating the grid for 13 states and Washington, D.C. Unlike energy-only ERCOT, PJM runs a mandatory capacity market (RPM) alongside energy and ancillary services — and that capacity signal has exploded: the 2027/2028 Base Residual Auction cleared at the FERC-approved price cap of $333.44/MW-day across the entire footprint, the first auction in which the whole RTO fell short of its reliability requirement, driven largely by data-center load growth. A battery here stacks three revenue streams — capacity payments, frequency regulation, and day-ahead / real-time energy arbitrage — but with roughly 67 GW of storage now sitting in PJM’s reopened interconnection queue against only a few hundred MW operating today, the constraint is grid access, not appetite. Live day-ahead LMP data is being integrated for this page; no arbitrage spread is shown until it is grounded in real prices.

333.44$/MW-day

2027/28 capacity auction — cleared at FERC price cap, whole RTO

67GW

Battery storage in PJM’s reopened interconnection queue

43GW

Storage PJM needs by 2045 (Brattle) vs. a few hundred MW live today